EP1375361B1 - Corrugated board provided with a tear line - Google Patents

Abstract

The corrugated cardboard has a single corrugated layer (14) between two cover sheets (12a, 12b). These have tear lines (18) passing through at least 50% of their thickness, the corrugated layer being uncut or only cut at the peaks of the corrugations.

Description

The invention relates to corrugated cardboard in a single-shaft design with corrugated paper, which is connected on both sides with two cover papers is and has a tear line along which the Corrugated board is rupturable, with the two ceiling papers along the tear line are cut on both sides.

Corrugated board is used as a material for many transport, Um- and in Recently also increasingly used for sales packaging. In addition to the transport protection to many of these packaging even more requirements. One of them is that the packaging is simple, reliable, safe and easy can be opened. For this purpose, have conventional corrugated board Perforations or similar cutting combinations along the Tear line on. In part, these perforations are through supports a pasted tear thread made of tear-resistant material, which is designed to make tearing more reliable.

From DE 197 05 533 an arrangement for forming a Tear line for solid and compact board known in which the Cardboard on both sides by a distance of a few millimeters has offset scratches. When tearing the tears Cardboard in the paper plane between the bottoms of the scratches. However, that method is not transferable to corrugated board, because there is no homogeneous material.

GB 777,079 discloses a single-walled corrugated board with tear lines, alternatively, continuous cuts made in the cover papers are only cut in (ie the cover papers not cut completely) or a broken one Perforation, however, the blankets complete cuts are proposed. In any case, the spaced on both sides tears, so that when tearing open an unclean tear edge. Of the The preamble of claim 1 corresponds to this state as Tecknik.

DE 693 00 351 T2 discloses a tearing device for Corrugated cardboard in which a tear tape is provided, and On both sides of the tear strip lines of weakness and these opposite on the back cover paper more Weakening lines are provided. Such a construction has some significant disadvantages. That's the construction structurally more elaborate, and it can not be round or arched Tear lines run as the tear tape made of plastic is glued to the cardboard blank. In addition, the design freedom in terms of the arrangement of the tear line due to their Straightforwardness significant restrictions.

The known tear-open systems were able to meet the requirements an easy-to-open, yet unrestricted stable Do not fulfill the packaging. The relevant reason lies in the technical contradiction between on the one hand the weakening the material of the corrugated cardboard for the opening process and on the other hand the preservation of the stability of the material for the Transport protection. The known systems all try one, one To find compromise from these two diametrical requirements.

For example, from the publication "Transport packaging from Solid and corrugated board of the European Trade Institute (EHI) As can be seen from page 13, the conventional systems are all unsatisfactory (not suitable). On page 30 of this publication from the 1998 results that boxes with Perforations need to be time consuming to open and that Staff is misled for the risky use of knives. Furthermore, the use of knives often leads to one unwanted extraordinary damage to the packaged goods.

Object of the present invention is therefore, the tear line form a generic corrugated cardboard in such a way that a simple production waiving a tear tape is possible, wherein the corrugated cardboard at the intended opening areas easy and reliable to open without that the required stability of the corrugated cardboard essential is impaired and is clean during the tearing process, form smooth tearing edges.

In other words, the invention is intended to maintain stability corrugated board to ensure high efficiency Packing processes and securing the packaged goods during the Transportes serve, on the other hand, easily and reliably defined points, namely the predetermined tear line, To be open and this should be especially clean edges after opening to prevent cuts and to Ensuring optimum optics. The optics is particularly important in display and sales packaging, in which from the corrugated container for receiving goods are made on retail shelves, for example by Supermarkets, be set up.

The object is solved by the features of claim 1.

Advantageous developments of the invention will become apparent the dependent claims.

Due to the fact that in the invention only the ceiling papers are cut across each other while the Wave structure not or only insignificantly (along the wave crests or troughs) is cut, is the mechanical Stability of the corrugated hardly affected. At the Tearing process, the cut ceiling papers look like Knife edges that cleanly and non-cutting the wave paper to the cut by a shearing cut, what about clean and visually appealing cutting edges leads. The wave paper is between the top cover paper one side and the bottom cover paper the intersected the other side.

In other words, the invention serves to maintain stability the corrugated board to ensure high efficiency during packaging processes and the securing of the packaged goods during on the other hand, it is light and reliable at defined locations, namely the predetermined tear line, to open and this ensures above all clean Edges after opening to prevent cuts and to ensure an optimal look. The optics is particularly important in display and sales packaging, in which from the corrugated container for receiving goods are made on retail shelves, for example by Supermarkets, be set up.

It is an advantage if the cover papers cut 100% become. With less cutting depth in the cover papers or with a lateral offset of the opposite Cuts in the ceiling papers larger than 1.5 mm is the special function of the effect of tearing edges as Shearing edges are not guaranteed, which is usually too dirty Cutting edges leads.

According to the invention, the depth of cut can be selected such that that the cut is not just the cover papers completely severed but also slightly penetrates into the shaft paper, so that this is marginal along the wave crests are cut. The depth of cut should not exceed 5% of the distance between the two cover papers, a significant weakening of mechanical stability to avoid. When it comes to "wave paper", that's it meant single or multi-ply paper.

Alternatively, it is also possible to choose the depth of cut that the cut the cover papers not completely, but more than 50%, preferably more than 80%, while the wave paper is not cut thereby. at This training is the cutting effect of the invention not as good as completely severed cover papers and thus the tearing edges are not correspondingly smooth. Therefore the strength of the corrugated cardboard is something in the area of the cuts better than deeper cuts, especially those which penetrate into the corrugated paper.

Preferably, the cuts are in the two cover papers face each other directly opposite the plane of the corrugated board. A lateral offset of up to 1.5 mm, better of less than 0.5 mm between the opposite cuts of the front and the back still reach a limited extent the beneficial effects of the invention. At a larger one lateral offset no more cutting effect, Rather, the wave paper is then only torn, which is too visual unsightly tearing edges leads.

Most optimal are the results of the invention, when the tear line approximately perpendicular to the wave direction runs. In this context, under "wave direction" understood the direction in which the wave paper straight runs. The smaller the angle between the tear line and wave direction, the more the fiber direction affects of the corrugated paper adversely affects the appearance of the separating edge out.

According to an advantageous embodiment of the invention is this through a greater depth of cut and thus to an increased Cutting the wave crests balanced, provided the Angle between tear line and wave direction is larger, in particular more than about 30 degrees. Thereby make even tears with curves is no problem and it will possible complex curved tear-open mechanisms for the production sell-through display and sales packaging, as mentioned for example in DE 197 05 533, reliable in Implement corrugated board. Compared to that described in EP 571 197 B1 Draws method with pasted tear tape the invention is characterized by the advantage that displays with rising side walls or higher back walls can be realized.

At an even smaller angle between the tear line and Wave direction of preferably less than 30 degrees is according to an advantageous development, the cutting line wave-like formed, either by a wave-like Cut or by using serrated knives, whereby the depth of cut is kept within tolerable limits can.

The greater the depth of cut and thus the cutting of the Wellenpapieres is, the lower the relative effort when tearing the corrugated board. This effort decreases disproportionately with increasing depth of cut, while the relative weakening of stiffness to the same extent disproportionately increases, since with increasing cutting depth the Length of the severed wave paper disproportionately decreases, but especially for the rigidity of corrugated cardboard important areas of the wave structure with large Anstellwinkel only cut at a large depth of cut become. It follows that with slight cutting the wave mountains the stability of the corrugated cardboard relatively little decreases, but the corrugated much easier to rip is.

The longer-fibred the cover papers compared to the wave paper are, the easier it is to rip open the corrugated board. On the other hand, reduces the rigidity of the tear line provided corrugated cardboard relatively least, if the Shaft paper is long-fibrous than the cover papers.

Figur 1:

Eine schematische perspektivische Darstellung einer erfindungsgemäßen Wellpappe beim Schneidevorgang;

Figur 2:

den Schneidevorgang gemäß Figur 1 in schematischer Seitenansicht;

Figur 3:

eine Schnittdarstellung der Wellpappe mit teilweise eingeschnittenem Wellenpapier;

Figur 4:

die Wellpappe beim Aufreißvorgang;

Figur 5:

drei Varianten von Einschnitten in eine Wellpappe;

Figur 6:

eine beispielhafte Anwendung der Wellpappe für einen ersten Verpackungskarton;

Figur 7:

eine beispielhafte Anwendung der Erfindung für einen zweiten Verpackungskarton.

The invention will be further elucidated on the basis of preferred exemplary embodiments and the accompanying drawings, in which:

FIG. 1:

A schematic perspective view of a corrugated cardboard according to the invention during the cutting process;

FIG. 2:

the cutting process of Figure 1 in a schematic side view;

FIG. 3:

a sectional view of the corrugated cardboard with partially cut shaft paper;

FIG. 4:

the corrugated cardboard during the tearing process;

FIG. 5:

three variants of incisions in a corrugated cardboard;

FIG. 6:

an exemplary application of the corrugated cardboard for a first packaging board;

FIG. 7:

an exemplary application of the invention for a second packaging box.

In Figure 1 , a corrugated cardboard 10 is shown in perspective, which consists of an upper ceiling paper 12a and a lower Dekkenpapier 12b and an interposed therebetween and with two ceiling papers 12a, 12b glued corrugated paper 14 . The corrugated paper 14 is rectilinear in the wave direction 16 and wave-shaped perpendicular thereto. As shown in Figure 1, the tear line 18, along which the corrugated board is to be torn later, is formed by cutting the cover papers 12a, 12b by means of two knives 20a, 20b , the two sections being superimposed with respect to the corrugated board plane, that is none have lateral offset to each other.

As is clear from Figures 2a and 2b, can by means of the blades 20a, 20b, either only the liners are cut through without the corrugated paper is concerned 14 (Fig. 2a) or the corrugating medium 14 is also scribed in the region of the wave crests 22 (Fig. 2b).

In Figure 3 is shown enlarged, to what extent a scoring of the corrugated paper 14 is carried out according to the invention. The depth of cut 24 on each side is preferably not more than 5% of the distance between the two cover papers 12a, 12b, ie the thickness of the corrugated board 10. Thus , along the cutting lines, the corrugated paper 14 is only present in fragments, but this does not significantly reduce it at small depths of cut the stiffness and strength causes.

FIG. 4 schematically shows the tear-open process in perspective. The corrugated cardboard 10 is thereby torn open along the tear line 18, which is also the cut in the upper cover paper 12a , wherein the tear edges forming thereby simultaneously act as shearing edges 26a, 26b , which ensure a clean and smooth cutting through of the wave paper 14 . This function is ensured, in particular, when the two cover papers 12a, 12b are completely cut through. Otherwise, no sharp-edged shear edges can form if the cover papers themselves have to be partially torn.

In FIG. 5 , three sectional variants in a corrugated cardboard 10 are shown to illustrate the invention, the thicknesses of the two cover papers 12a, 12b being shown enlarged in relation to the extent of the corrugated paper 14 for reasons of illustration. The first cuts 40a, 40b cut 100% of the cover papers 12a, 12b without appreciably penetrating the corrugated paper 14 . The second cuts 42a, 42b penetrate about 60% into the cover papers 12a, 12b , the wave paper 14 is not cut. The third cuts 44a, 44b completely cut through the cover papers 12a, 12b , and the corrugated paper 14 is cut to about 10% (the distance a between the cover papers 12a, 12b ). The third cuts 44a, 44b also have a lateral offset b that is less than 1.5 mm.

In FIG. 6 , an exemplary application of the invention for a corrugated box 28 (so-called "American Case") is shown in perspective, wherein the corrugation direction of the corrugated cardboard 16 is shown (the direction of the arrow or the lines). This corrugated box 28 includes a tear tab 30 which is formed by the circumferential tear line 18 . As a result, the tear line 18 can be formed such that the tear tab 30 can be removed without the aid of knives, etc., leaving clean and smooth tear edges. In that region in which the tear line 18 runs parallel to the wave direction 16 , a wave-like tearing line 32 can be used instead of the straight line. At angles between 0 ° and 90 °, the depth of cut may be greater than in those areas where the tear line 18 is perpendicular to the shaft 16 direction.

FIG. 7 shows a further exemplary application of the invention for an outer packaging carton 50 in which the wave direction of the wave paper is represented by the arrows w. The almost arbitrarily shaped cutting line 52 , which may be rectilinear or arcuate, is shown in FIG.

In the case where the cut line is parallel to the wave direction w (shown in dashed lines), a wave-like (reciprocating) cut line 54 may be useful to achieve a mean weakening of the wave structure, while in the case of a straight cut line depending on the wave structure in the section line a very large or no weakening of the wave paper is possible.

Claims (6)

1. Corrugated paperboard of single fluted type comprising a corrugating medium (14) joined at both sides to two liners (12a, 12b) and a tear line (18) along which the corrugated paperboard (10), without the need of a tear tape, can be torn open, the two liners (12a, 12b) being nicked along the tear sline (18) on both sides, characterized in that the nicks in the two liners (12a, 12b) sever the liners (12a, 12b) at least to 50%, whilst the corrugating medium (14) is not at all nicked or only in the region of the corrugation peaks, and the nicks are located facing each other in the two liners (12a, 12b) and the tear line (18) being configured straight or curved, so that the liners (12a, 12b) on being torn open sever the corrugating medium (14) like scissor edges.
2. The corrugated paperboard as set forth in claim 1, characterized in that nicks in the two liners (12a, 12b) sever them to 80%-100%.
3. The corrugated paperboard as set forth in claim 1, characterized in that at an angle of more than 70° between tear line (18) and fluting direction (16) the liners (12a, 12b) are totally severed and the nick depth on both sides in the corrugating medium (14) amount to 5% of the spacing between the two liners (12a, 12b).
4. The corrugated paperboard as set forth in claim 1, characterized in that at an angle from 30° to70° between tear line (18) and fluting direction (16) the liners (12a, 12b) are totally severed and the nick depth on both sides in the corrugating medium (14) amount to 10% of the spacing between the two liners (12a, 12b).
5. The corrugated paperboard as set forth in claim 1, characterized in that at an angle of more than 75° between tear line (18) and fluting direction (16) the nick lines are wavey.
6. The corrugated paperboard as set forth in any of the claims 1 to 5, characterized in that the tear line (18) consists of multiple line portions differingly angled between tear line and fluting direction and that differing nick depths and nick line shapes are provided as a function of the magnitude of the angle.

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